A Fast Prediction Approach of Radiated Emissions From Closely-Spaced Bent Cables in Motor Driving System

Abstract

Three-phase cables in a motor driving system are the major ways of electromagnetic radiation, which result in potential interference to the nearby electronic equipment on electric vehicle. Numerical simulation of radiated emissions from cables is time-consuming, which becomes insufficient to compute large numbers of cables for actual applications. Hence, this article proposes a fast prediction approach that can highly improve the computational efficiency. Since cables are often close to each other and arbitrarily bent in the real application due to confined working space, the influence of proximity effects caused by closely-spaced cables on radiated emissions is also considered in the calculation model by multi-transmission line and Hertzian dipole theories. Besides, an equivalent model is presented to characterize the measured motor impedance. On the basis of the proposed cables model, a complete motor driving system model is originally developed by integrating a radiated electromagnetic interference (EMI) source model of inverter and a load equivalent model of motor impedance. The system model is of vital value to identify the mechanism concerning radiated EMI issues on electric vehicles and efficiently evaluated in the end. Both numerical simulations and experiments are conducted for the validation of proposed approach, which show that the proposed approach can save over 90% computational time with desired evaluation accuracy.